WASHINGTON — There could be an unlikely contributor to the decline of marriage in this country. And it’s free pornography on the Internet.

A U.S. team of researchers, who published their findings in The Institute for the Study of Labor (IZA) in Germany, determined that the rise of free Internet pornography is not only correlated with a pronounced decline in percentage of young adult males who are married, but might actually be contributing to the trend.

“The results in this paper suggest that such an association exists, and that it is potentially quite large,” the study notes.

The researchers used data from the General Social Survey (GSS), a comprehensive, nationally representative survey, to analyze how 18-to-35 year-old men used the Internet between 2000 and 2004. They focused on how many hours each participant spent on the Internet per week, and how many reported having used the Internet to view pornography in the past 30 days, but also observed other activities, including the use of religious websites.

“We asked ourselves, what is helping determine whether people are married or not?” said Michael Malcolm, a professor at the University of West Chester, Pennsylvania, and one of the study’s authors. “One of those things, we thought, could be the use of pornography.”

To test the hypothesis, Malcolm adjusted for a number of variables, including age, income, education, religiosity and employment, all of which have been shown to correlate with marriage. He also adjusted for the possibility marriage has an impact on pornography use, and never the other way around.

He then measured the correlation between pornography use and marriage rates among the more than 1,500 participants studied.

Broadly, higher Internet usage was associated with lower marriage rates. But pornography use in particular was more closely linked to those participants who were not married than any other form of Internet use, including regular use of financial websites, news websites, sports websites, and several others. The opposite, for comparison, was true for religious website use, which was positively correlated with marriage.

The natural reaction might be to dismiss the findings as confirmations of an obviousness: that men who are married tend to look at porn less frequently precisely because they are married. While that might very well be true, and likely helps explain some of the relationship, it doesn’t explain all of it.

The researchers, while careful to say that their findings fall short of being conclusive, insist that the relationship between the two also “likely runs in the direction that we assert.”

The reason, Malcolm explains, is likely tied to the relationship between marriage and sexual gratification. If pornography is viewed as a means of alternative sexual gratification, then it could be undercutting the need for marriages to serve this function, at the very least during a younger age. Think of it as a milder form of premarital sex.